In a computerized content delivery network, first-party content providers can provide information for public presentation of resources, such as web pages, documents, applications, and/or other resources. Additional third-party content can also be provided by third-party content providers for presentation on the client device together with the first-party content provided by the first-party content providers. Thus, a user viewing a resource can access the first-party content that is the subject of the resource as well as the third-party content that may or may not be related to the subject matter of the resource.
User experience in viewing the resource is very important for both for first-party content providers and third-party content providers. In order to improve the user experience, many first-party content providers control the look-and-feel of the third-party content by using closed ad servers that provide only advertisements that are specifically designed for each resource.